The primary aim of this research is to develop test systems, either in vitro or in vivo, for chemotherapeutic agents potentially useful in the treatment of cancer of the prostate. Major emphasis has been put on the effects of drugs on a number of enzyme systems related to androgen metabolism in the prostate, i.e., 5 alpha-reductase (rat), arginase (rat) and the system responsible for deposition of steroids in the prostate of the dog. More recently, the metabolism of zinc 65 in the prostate of rats, dogs and baboons has been an area investigated in our laboratory, with the hope of establishing zinc metabolism in the gland as a sensitive index of the effects of hormones and chemotherapeutic drugs on the prostate of animals. BIBLIOGRAPHIC REFERENCES: Sandberg, A.A., Kirdani, R.Y., Yamanaka, H., Varkarakis, M.J. and Murphy, G.P.: Potential test systems for drugs against prostatic cancer. Cancer Chemo. Reports 59: 175-184, 1975; Varkarakis, M.J., Kirdani, R.Y., Murphy, G.P. and Sandberg, A.A.: Anti-prostatic effects of a nitrogen mustard of estriol. Proc. Soc. Exptl. Biol. and Med. 148: 904-908, 1975.